Rapid and Green Production of Mo2C Nanoparticles with High Photo-Thermalization via Single-Step Femtosecond-Laser Irradiation

Abstract

Photothermal cancer therapy demands nanomaterials with specific traits, including selective absorption of biotransparent near-infrared (NIR) light, efficient light-to-heat conversion, biocompatibility, dispersibility, and prolonged temporal stability. These desirable properties are achieved by synthesizing Mo₂C nanoparticles via an environmentally friendly femtosecond-laser ablation method. Mo₂C flakes are dispersed in water and treated with different laser powers for different durations. This process produces Mo₂C nanoparticles in a single step in 10 min with water as the only additional material, forming stable colloidal solutions with no contaminants or hazardous waste. Structural and compositional characterization indicates laser-induced amorphization of the nanoparticles, including gradual oxidation that enhances NIR light absorption. Notably, the Mo₂C nanoparticle solution prepared using a 1.6-W laser power in 10 min demonstrates photothermal conversion efficiencies exceeding 45% and 50% and temperature increases of 21 and 22 °C when illuminated with biotransparent 800 and 1064 nm NIR light, respectively. Furthermore, the solution exhibits exceptionally stable photothermal behavior over 6 months. These Mo₂C nanoparticles, prepared by a rapid and clean laser manufacturing method, hold great promise for advancing photothermal therapy to combat cancer noninvasively.